Danfoss VLT AAF00x Instruction Manual page 25

How to Install
Back cooling
The design of the active filter is built on a back channel
cooling system where 85% of all heat is ducted via an IP54
segregated back channel. This reduces the needed airflow
inside the enclosure and ensures less moist and dust
ventilation across vital components.
The back channel air is normally ventilated via the plinth
4 4
inlet and ducted out the top of the enclosure. The design
of the back channel does, however, also allow air to be
taken from outside the control room and dusted back out
again. This is supported to ease stress on the control room
air conditioner and so conserve energy. To support back
wall inlet, the unit air inlet has to be blocked via an
optional cover and the air outlet ducted via an optional
top duct.
NOTE!
A door fan is required on the enclosure to remove the
heat losses not contained in the back channel of the unit
and any additional losses generated from other
components installed inside the enclosure. The total
required air flow must be calculated so that the
appropriate fans can be selected. Some enclosure
manufacturers offer software for performing the
calculations (e.g., Rittal Therm software).
Airflow
The necessary airflow over the heatsink must be ensured.
The flow rate is shown below.
Enclosure
Frame size
Door fan
Heatsink
Table 4.1 Heatsink Air Flow
NOTE!
For the active filter, the fan runs for the following reasons:
1. Active filter running
2. Specific heatsink temperature exceeded (power
size dependent)
3. Specific Power Card ambient temperature
exceeded (power size-dependent)
4. Specific Control Card ambient temperature
exceeded
Once the fan is started, it will run for a minimum of 10
minutes.
4-12
IP21 / IP54
D13/D9 E9, E7
3 3
340m /h (200 cfm) 340m /h (200 cfm)
3 3
765m /h (450 cfm) 1230m /h (725 cfm)
MG.90.V2.22 - VLT
VLT Active Filter AAF 00x
External ducts
If additional duct work is added externally to the Rittal
cabinet, the pressure drop in the ducting must be
calculated. Use the charts below to derate the unit
according to the pressure drop.
(%)
90
80
70
60
50
40
30
20
10
0
0
Figure 4.16 D frame Derating vs. Pressure Change
Air flow: 450 cfm (765 m
(%)
90
80
70
60
50
40
30
IP21/54
20
10
0
0
Figure 4.17 E frame Derating vs. Pressure Change
Air flow: 725 cfm (1230m
4.3.6 Connector/Conduit Entry - IP21
(NEMA 1) and IP54 (NEMA12)
Cables are connected through the gland plate from the
bottom. Remove the plate and plan where to place the
entry for the connectors or conduits. Prepare holes in the
marked area on the drawing.
®
is a registered Danfoss trademark
0.5 4.9 13 27.3 45.9 66
Pressure Increase
3 /h)
0 0.1 3.6 9.8 21.5 43.4
Pressure Change
3 /h)
89.3 115.7 147
(Pa)
76 147.1 237.5 278.9
(Pa)